Pneumatic for mechanical musical instruments.



P'ATENTED JUNE 30, 1908.

' A. z-QULBRANSEN.'

PNEUMATIQ FUR MECHANICAL MUsIAL-INSTRUMBNTS.

f 'APPLICATION FILED SEPT.12. 1906.

UNITED sTATEs PATENT oEEicE.

AXEL G.GULBRA'.\'S1'I\', Oi` CHICAGO, ILLINOIS, ASSIGNOR TO GULBRANSEN, DICKINSN COMIN Y, Or1 VIIIUAGO, ILLINOIS, A. CORPORATION OF ILLINOIS.

PNEUMATIC FOR MECHANICAL MUSICAL INSTRUMENTS.

Specification o f Letters Patent.

Patented .nine 3o, 190s.

A plcation filed September 12, 1906. SerialNo. 334,241.

To all whom it may concern:

Be it known that I, AXEL G. GULBRANSEN, citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented a certain new and useful Improvement in Pneumatics for Mechanical Musical Instruments, of which the following is a full, clear, concise, and exact description, reference being had to the .accompanying drawings,- forming a part of this specili'cation.

My invention relates to primary pneumatic mechanisms, particularly to such lmechanisms adapted to be used in mechanical musical instruments, such as pianos, and the object of my invention 1s to provide more simple, more compact and more efficient construction and arrangement of such mechanisms.

The various features of my invention will be best understood and described by reference to the accompanying drawing, in which- Figure 1 1s a side view of a pneumatic mechanism; Fig. 2 is a top view thereof; Fig. 3 is a sectional view taken on plane 3 3 of Fig. 1 Fig. 4 is a top View, the part above plane 4-4 of Fig. 1 being removed; and Fig. 5 is a vertical sectional view taken on plane 5-5 of Fig. 2.

The primary pneumatic mechanism here shown is adapted for association with the abstract rods of a piano, and the bellows and valve mechanisms' are all comprised lin a small and compact unitary structure, these variousstructures, as described in m copending application, Serial No. 331,230, filed August 20, 1906, being arranged in staggered rows, and connected at their front ends with the rear wall of the low pressure chamber running along the lower part of the piano casing to the rear of the drop board. This low pressure chamber is represented in the drawing by 1, the primary pneumatic mechanisms being screwed toits rear wall`2` by means of screws 3. Each rimary mechanism has a main mounting block 4 frein the lower side of whichare suspended any number'of bellows 5, 6, and so on, arranged in a vertical tier, the swinging members 7 of the bellows being all connected together through links S, and one of the'swingingmembers having a cushioned abutment or ext .nsion 9 for engagement with some member connect- 'ing with the hammer-actuating mechanism of the instrument.' In the front end of the mounting block areA the upper and lower dia-- phragm chambers 10 and 11 separated bythe diaphra m 12 whose edges are glued to the annularedge 13 between the chambers. In the rear of the mounting block are the upper and lower auxiliary diaphragm chambers 14 and 15 separated by the auxiliary dia `hragm 16 secured at its edges to the annular edge 17 between the chambers. Secured over the mounting block is the valve block 18 which forms the roof ofthe upper diaphragm chambers 10 and 14. Concentric with the main diaphragm chambers is the valve chamber 19 in the valve block in which is the ball valve V20 which may be of any material but is prefwhichextends a valve stem 24 having the upper and lower valveheads 25 and A26, the lower valve head being in position to be engaged by the auxiliary diaphragm when said.

diaphragm is raised. Inthe center of the mam diaphragm is a block 27 for engaging with the valve when the main diaphragm is "raised,

A channel or assageway 28 leads from the rear end of t e valve yblock and passes throughthe valve block to a vertical passageway 29 which connects with the passageway 30 leading through the lmain' mounting block to the lower auxiliary diaphragm chamber 15. The chamber or o ening 23 is connected with the lower main iaphragm chamber 11 through passageways 31 and 32 through the valve and mounting blocks, respectively. The Aupper diaphragm chambers connect together through the passage- 'way 33, and the lupper main diaphragm chamber connects with the low pressure chamber 1 through passageways 34 and 35 cut respectively in t rear wall 2. The cates with the trac erboard t ough the passageway 36 and is also in communication with the low pressure chamber through passageway 37v over whose outlet is secured the washer or disk 38 having the pin hole or .perforation 39. The valve chamber 19 connects with the lower bellows 6 throughchalnels 40 and 41 and is connected with. the

e mounting block and assagewar 28 communi- 2 ist 42 and 43,

nectedy therewith being thus in communica' tion with atmosphere and the bellows distended. The auxiliary valve is normally also in its lower osition, its upper head 25 closing the ,cham er 23 to atmosphere'and 'connecting said chamber with the upper auxiliary diaphragm chamber.

ber as access to all the diaphragm chambers when the diaphragme are down. This air passes tothe upper diaphragm chambers through the passageways 34, 35, and. the connecting passageway 33, the lower main diaphragm chamber being normally inv communication with the upper auxiliary diahragm` chamber, and the lower auxiliary iaphragm chamber receiving this low pressure' air through the perforation 39 an l passageway 36. As the music sheet, however, travels over the trackerboard the passageway 36 is o cned and atmospheric air immediately rus es down said passageway into the passaway 28 and into the lower auxiliary diap agm chamber, causing the. auxiliary diaphragm to be quickly blown up wardly, .the lower valve head being raised to close the lower o ening Aof the chamber 23,

,and the upper va ve head 25 being raised tov connect said chamber' with atmos here. Atmospheric air therefore imme lately rushes into chamber 23 and through passageways 31 and 32 to the lower main diaphragm chamber, causing the main diaphragm to be blown u wardly, whereupon the block 27 strikes t e ball .valve and this valve 'is raised from its lower seat into engagement with 1ts upper seat. The connection to atmosphere from the valve chamber is therefore closed and the valve chamber connected directly with the low pressure chamber 1, and the bellows are therefore then also connected With the low pressure chamber and immediately colla se, these bellows acting all cumulatively, t eir combined force being transferred to the abutment 9 through the"` thetraclrelboardin order to assure that the ,1119519 Sheetopemngs at all ltimes register ex- .aflamththc trackerboard Org-emerga.. lll/'ith Norma ly i low ressure air irom/ the low pressure cham- Alows'- Although aux'liary yalving nu l ,main supporting bloei-L' et, a bellows 5 havuig outside ce this arrangeinentlciz pri; music sheet yopenings need not be v but can be very much Tower Y trackerboard openings, little i pheric air is required te ope/rat., the auA valve. This-auxiliary Valve nature of a relay valve, l' being necessary to raise tf. lower main diaphragm chamber e i lrectly connected with atmosphere v,lncugh a large passageway, and 'the air coming in through this large passageway' ope the main diapluagm and valve instead oair `admitted through the music sheet, Thus the music sheet may be allowed a wide range so of displacement or relative n'fc Yement u. respect to the traclcrboard Author 'y way influencing the amount of to operate the auxiliary t f. l music sheet again closes e t', opening the valves fall back to t position, for the reason that t" 1 the diaphragme returns Le r pressure by virtue oi the equalizing pin` lopening 39. The bellows become dicten immediately after the ball leaves the and allows atmospheric air to 'llow to the 'os ism may have been useojiu yconsce/tisi primary valving .in echanism, l 'thin' the first to incorporate such mechanisms l gether with the /bellows in unitary, and compact structure es C' scribed in the copendii ferred to, the paralleling ci described is much more el" as the response ol the bellows to cpe the trackerboard passo 7' quicker' than any mechanisms gle, comparatively long bellows ployed. This paralleling of the c assists in producing compact structure there is a ways more ro' an instrument such a pA room horizontally.

Having thus descibeV my inver-if claim as new and desire to secure byi.. Patent the following claims:

l. ln pneumatic mechanism ier mec 'ally operated pianos, the combinatie;

below tie mounting blick, said nrc` block forming the top of said cell y second bellows 6 supported i ing block and disposed i bellows 5, a rod 8 manne nog parts of the bellows, valv'e chamber il diaphragm in said chamber, valve block i8 over the mounting block; a valve-opening l!) through said valve block, a ball valve 20 con-l trolling said o ening and dispose( directly above the diapi ragm to be actuated thereby, a secondary Valve .oui through "l' valve block, spool-af head 26, a second daphra n1 chambe l5, a

A diaphragm 16 in said cham ey for controlling theI movements of the, secondary valve, a

reservoir, connections between the reservoir and the diaphragm chambers, and a Connection between elle reservoi and ybellows Toontrolled by the valves. l

2. In pneumatic mechanism for mechanic-l ally operated pianos, the combination of a Asupporting frame forming a reservoir, 'a Valve block supported and extendn from said Suopo'rting frame, .a bellows below jghe blool, salv bool; formmg the evatlonary upper Wall of lle bellows, a valve block. on thesupnortlng block, an outlet through said Valve block to atmospbeze, ball Valve Controlling said ou let, a diaphragm chamber Within the supporting block, a-{laplu'agm Wihr; the daphragm chamber'for controlling the operacion` of the 'ball Valve, e. Second opening through the valve block, a spool-bape seoondary valve controlling the 510W through ysaid ,second passageway, a second diaphragm chamber, a diaphragm in said seoond diaphragm chamber for controlling the operations of the secondary valve, an outletlo atmosphere, connections between the diaphragm ohambes and the reservoir, opening of Sad. atmosphere outlet oa'usug'aotuaton of the secondary valve to connect the flfst diaphragm chamber with atmosphee 'to cause aot-uatioo of the ball valve; 4and oonneotons between the bellows and 'eser'vor opened 'upon such actu ation of the ball valve.

In Witness whereof, l hereunto subscribe my name this 8th day of bepember A. D.,

AXEL G. GULBRNSEN.

Vnesses: I p

CHARLES JT. SUHMDT, FREE W. loEEN` 

